As I was saying , this is caused by weak capacitors on the power board.
If you or a friend is handy with a solder iron then you can buy a capacitor kit for this model at the link below;
This kit comes with everything you need except the solder iron.
Also note that there are instructions and videos available on that page that shows you how its done.
If you are not into repairing this yourself then a tv repair shop could replace those capacitors for you for approx. $75 to $100
If you go for the repair shop option then click on the link below and enter your zip code ;
This will give you a list of repair shops in your area.
You could give a call to different shops in your area with the info you have now to get an idea of their rates , this is a bit like buying insurances , it pays to shop around.
By the way if you are to take it to a shop , you should still get the capacitors kit as I`m sure you would save money on the cost of the parts.
Hope this help and I will be in standby if you have any questions.
Thank you and please take the time to rate my answer if that answers your question and you can still reach me here at anytime after this chat is closed if you have other questions.
Please note that from where i`m sitting there is just so much that i can do and if you are going to rate my answer below O.K service then please do not rate at all , just let me know.